Heckling, much like stand-up comedy, is an artform all on its own and it takes practice and perserverance to truly perfect it. Say the stand-up "comedian" starts off his set and he's killing. Absolutely slaughtering the crowd. Now your friends have always told you that you're a freaking riot. Especially when you're drunk so let's get you really drunk.
Now that you're on the road to blacking out you've begun to realize that you're no longer afraid of making an ass of yourself in front of a crowd of complete strangers. You're already well on your way to making this a memorable show for all parties involved.
Here's what you do now. Sometimes comedians will tell long drawn out stories, pulling the audience in and really building up the tension to be released, then right before they tell the side-splitting punch line, during that very brief but intense silence, you yell "WHERE'S THE PUNCHLINE GUY?" and now you've single-handedly ruined the fun and relaxing atmosphere of a comedy show.
Beware of backlash from comedians who are more often than not quick-witted and sharp-tongued. Watch out for an even funnier comeback to your heckle, probably something relevant and comical like "I remember when I had my first beer." But because I've prepared you for this specific response you can counter with a gem like "Well shut up you, you ASSFACE." Congratulations, you just won your first heckling battle!
If you're really good at heckling you'll definitely get noticed by the crowd. Don't mind the looks of contempt and pity as you're escorted out of the building because you my friend, are onto bigger and better things. At this point you can expect your friends to act like they don't know who you are as you leave the building, they paid full price for this comedy show and they means to see it, but don't worry you'll make cooler, hecklier friends in this business. Above all, don't forget to scream right before the door closes in your face that you still have like, 2 sips of your beer left as the crowd boos you out.
So there you have it, the tools you need to ruin the success of others. Use them wisely for all future Carlos Mencia tapings that you attend.